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                        <h1 id="%E6%95%B0%E5%80%BC%E7%9A%84%E6%89%A9%E5%B1%95">&#x6570;&#x503C;&#x7684;&#x6269;&#x5C55;</h1>
<h2 id="%E4%BA%8C%E8%BF%9B%E5%88%B6%E5%92%8C%E5%85%AB%E8%BF%9B%E5%88%B6%E8%A1%A8%E7%A4%BA%E6%B3%95">&#x4E8C;&#x8FDB;&#x5236;&#x548C;&#x516B;&#x8FDB;&#x5236;&#x8868;&#x793A;&#x6CD5;</h2>
<p>ES6&#x63D0;&#x4F9B;&#x4E86;&#x4E8C;&#x8FDB;&#x5236;&#x548C;&#x516B;&#x8FDB;&#x5236;&#x6570;&#x503C;&#x7684;&#x65B0;&#x7684;&#x5199;&#x6CD5;&#xFF0C;&#x5206;&#x522B;&#x7528;&#x524D;&#x7F00;0b&#x548C;0o&#x8868;&#x793A;&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-number">0b111110111</span> === <span class="hljs-number">503</span> <span class="hljs-comment">// true</span>
<span class="hljs-number">0o767</span> === <span class="hljs-number">503</span> <span class="hljs-comment">// true</span>
</code></pre>
<p>&#x516B;&#x8FDB;&#x5236;&#x7528;0o&#x524D;&#x7F00;&#x8868;&#x793A;&#x7684;&#x65B9;&#x6CD5;&#xFF0C;&#x5C06;&#x8981;&#x53D6;&#x4EE3;&#x5DF2;&#x7ECF;&#x5728;ES5&#x4E2D;&#x88AB;&#x9010;&#x6B65;&#x6DD8;&#x6C70;&#x7684;&#x52A0;&#x524D;&#x7F00;0&#x7684;&#x5199;&#x6CD5;&#x3002;</p>
<h2 id="number-isfinite-number-isnan">Number.isFinite(), Number.isNaN()</h2>
<p>ES6&#x5728;Number&#x5BF9;&#x8C61;&#x4E0A;&#xFF0C;&#x65B0;&#x63D0;&#x4F9B;&#x4E86;Number.isFinite()&#x548C;Number.isNaN()&#x4E24;&#x4E2A;&#x65B9;&#x6CD5;&#xFF0C;&#x7528;&#x6765;&#x68C0;&#x67E5;Infinite&#x548C;NaN&#x8FD9;&#x4E24;&#x4E2A;&#x7279;&#x6B8A;&#x503C;&#x3002;</p>
<p>&#x5B83;&#x4EEC;&#x4E0E;&#x4F20;&#x7EDF;&#x7684;isFinite()&#x548C;isNaN()&#x7684;&#x533A;&#x522B;&#x5728;&#x4E8E;&#xFF0C;&#x4F20;&#x7EDF;&#x65B9;&#x6CD5;&#x5148;&#x8C03;&#x7528;Number()&#x5C06;&#x975E;&#x6570;&#x503C;&#x7684;&#x503C;&#x8F6C;&#x4E3A;&#x6570;&#x503C;&#xFF0C;&#x518D;&#x8FDB;&#x884C;&#x5224;&#x65AD;&#xFF0C;&#x800C;&#x8FD9;&#x4E24;&#x4E2A;&#x65B0;&#x65B9;&#x6CD5;&#x53EA;&#x5BF9;&#x6570;&#x503C;&#x6709;&#x6548;&#xFF0C;&#x975E;&#x6570;&#x503C;&#x4E00;&#x5F8B;&#x8FD4;&#x56DE;false&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-built_in">isFinite</span>(<span class="hljs-number">25</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">isFinite</span>(<span class="hljs-string">&quot;25&quot;</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isFinite(<span class="hljs-number">25</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isFinite(<span class="hljs-string">&quot;25&quot;</span>) <span class="hljs-comment">// false</span>

<span class="hljs-built_in">isNaN</span>(<span class="hljs-literal">NaN</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">isNaN</span>(<span class="hljs-string">&quot;NaN&quot;</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isNaN(<span class="hljs-literal">NaN</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isNaN(<span class="hljs-string">&quot;NaN&quot;</span>) <span class="hljs-comment">// false</span>
</code></pre>
<h2 id="number-parseint-number-parsefloat">Number.parseInt(), Number.parseFloat()</h2>
<p>ES6&#x5C06;&#x5168;&#x5C40;&#x65B9;&#x6CD5;parseInt()&#x548C;parseFloat()&#xFF0C;&#x79FB;&#x690D;&#x5230;Number&#x5BF9;&#x8C61;&#x4E0A;&#x9762;&#xFF0C;&#x884C;&#x4E3A;&#x5B8C;&#x5168;&#x4FDD;&#x6301;&#x4E0D;&#x53D8;&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-comment">// ES5&#x7684;&#x5199;&#x6CD5;</span>
<span class="hljs-built_in">parseInt</span>(<span class="hljs-string">&quot;12.34&quot;</span>) <span class="hljs-comment">// 12</span>
<span class="hljs-built_in">parseFloat</span>(<span class="hljs-string">&apos;123.45#&apos;</span>) <span class="hljs-comment">// 123.45</span>

<span class="hljs-comment">// ES6&#x7684;&#x5199;&#x6CD5;</span>
<span class="hljs-built_in">Number</span>.parseInt(<span class="hljs-string">&quot;12.34&quot;</span>) <span class="hljs-comment">// 12</span>
<span class="hljs-built_in">Number</span>.parseFloat(<span class="hljs-string">&apos;123.45#&apos;</span>) <span class="hljs-comment">// 123.45</span>
</code></pre>
<p>&#x8FD9;&#x6837;&#x505A;&#x7684;&#x76EE;&#x7684;&#xFF0C;&#x662F;&#x9010;&#x6B65;&#x51CF;&#x5C11;&#x5168;&#x5C40;&#x6027;&#x65B9;&#x6CD5;&#xFF0C;&#x4F7F;&#x5F97;&#x8BED;&#x8A00;&#x9010;&#x6B65;&#x6A21;&#x5757;&#x5316;&#x3002;</p>
<h2 id="number-isinteger-%E5%92%8C%E5%AE%89%E5%85%A8%E6%95%B4%E6%95%B0">Number.isInteger()&#x548C;&#x5B89;&#x5168;&#x6574;&#x6570;</h2>
<p>Number.isInteger()&#x7528;&#x6765;&#x5224;&#x65AD;&#x4E00;&#x4E2A;&#x503C;&#x662F;&#x5426;&#x4E3A;&#x6574;&#x6570;&#x3002;&#x9700;&#x8981;&#x6CE8;&#x610F;&#x7684;&#x662F;&#xFF0C;&#x5728;JavaScript&#x5185;&#x90E8;&#xFF0C;&#x6574;&#x6570;&#x548C;&#x6D6E;&#x70B9;&#x6570;&#x662F;&#x540C;&#x6837;&#x7684;&#x50A8;&#x5B58;&#x65B9;&#x6CD5;&#xFF0C;&#x6240;&#x4EE5;3&#x548C;3.0&#x88AB;&#x89C6;&#x4E3A;&#x540C;&#x4E00;&#x4E2A;&#x503C;&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-built_in">Number</span>.isInteger(<span class="hljs-number">25</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isInteger(<span class="hljs-number">25.0</span>) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isInteger(<span class="hljs-number">25.1</span>) <span class="hljs-comment">// false</span>
</code></pre>
<p>JavaScript&#x80FD;&#x591F;&#x51C6;&#x786E;&#x8868;&#x793A;&#x7684;&#x6574;&#x6570;&#x8303;&#x56F4;&#x5728;-2&#x2C6;53 and 2&#x2C6;53&#x4E4B;&#x95F4;&#x3002;ES6&#x5F15;&#x5165;&#x4E86;Number.MAX_SAFE_INTEGER&#x548C;Number.MIN_SAFE_INTEGER&#x8FD9;&#x4E24;&#x4E2A;&#x5E38;&#x91CF;&#xFF0C;&#x7528;&#x6765;&#x8868;&#x793A;&#x8FD9;&#x4E2A;&#x8303;&#x56F4;&#x7684;&#x4E0A;&#x4E0B;&#x9650;&#x3002;Number.isSafeInteger()&#x5219;&#x662F;&#x7528;&#x6765;&#x5224;&#x65AD;&#x4E00;&#x4E2A;&#x6574;&#x6570;&#x662F;&#x5426;&#x843D;&#x5728;&#x8FD9;&#x4E2A;&#x8303;&#x56F4;&#x4E4B;&#x5185;&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-keyword">var</span> inside = <span class="hljs-built_in">Number</span>.MAX_SAFE_INTEGER;
<span class="hljs-keyword">var</span> outside = inside + <span class="hljs-number">1</span>;

<span class="hljs-built_in">Number</span>.isInteger(inside) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isSafeInteger(inside) <span class="hljs-comment">// true</span>

<span class="hljs-built_in">Number</span>.isInteger(outside) <span class="hljs-comment">// true</span>
<span class="hljs-built_in">Number</span>.isSafeInteger(outside) <span class="hljs-comment">// false</span>
</code></pre>
<h2 id="math%E5%AF%B9%E8%B1%A1%E7%9A%84%E6%89%A9%E5%B1%95">Math&#x5BF9;&#x8C61;&#x7684;&#x6269;&#x5C55;</h2>
<p><strong>&#xFF08;1&#xFF09;Math.trunc()</strong></p>
<p>Math.trunc&#x65B9;&#x6CD5;&#x7528;&#x4E8E;&#x53BB;&#x9664;&#x4E00;&#x4E2A;&#x6570;&#x7684;&#x5C0F;&#x6570;&#x90E8;&#x5206;&#xFF0C;&#x8FD4;&#x56DE;&#x6574;&#x6570;&#x90E8;&#x5206;&#x3002;</p>
<pre><code class="lang-javascript">
<span class="hljs-built_in">Math</span>.trunc(<span class="hljs-number">4.1</span>) <span class="hljs-comment">// 4</span>
<span class="hljs-built_in">Math</span>.trunc(<span class="hljs-number">4.9</span>) <span class="hljs-comment">// 4</span>
<span class="hljs-built_in">Math</span>.trunc(-<span class="hljs-number">4.1</span>) <span class="hljs-comment">// -4</span>
<span class="hljs-built_in">Math</span>.trunc(-<span class="hljs-number">4.9</span>) <span class="hljs-comment">// -4</span>
</code></pre>
<p><strong>&#xFF08;2&#xFF09;&#x6570;&#x5B66;&#x65B9;&#x6CD5;</strong></p>
<p>ES6&#x5728;Math&#x5BF9;&#x8C61;&#x4E0A;&#x8FD8;&#x63D0;&#x4F9B;&#x4E86;&#x8BB8;&#x591A;&#x65B0;&#x7684;&#x6570;&#x5B66;&#x65B9;&#x6CD5;&#x3002;</p>
<ul>
<li>Math.acosh(x)    &#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x53CC;&#x66F2;&#x4F59;&#x5F26;&#xFF08;inverse hyperbolic cosine&#xFF09;</li>
<li>Math.asinh(x) &#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x53CC;&#x66F2;&#x6B63;&#x5F26;&#xFF08;inverse hyperbolic sine&#xFF09;</li>
<li>Math.atanh(x)    &#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x53CC;&#x66F2;&#x6B63;&#x5207;&#xFF08;inverse hyperbolic tangent&#xFF09;</li>
<li>Math.cbrt(x)    &#x8FD4;&#x56DE;x&#x7684;&#x7ACB;&#x65B9;&#x6839;</li>
<li>Math.clz32(x)    &#x8FD4;&#x56DE;x&#x7684;32&#x4F4D;&#x4E8C;&#x8FDB;&#x5236;&#x6574;&#x6570;&#x8868;&#x793A;&#x5F62;&#x5F0F;&#x7684;&#x524D;&#x5BFC;0&#x7684;&#x4E2A;&#x6570;</li>
<li>Math.cosh(x) &#x8FD4;&#x56DE;x&#x7684;&#x53CC;&#x66F2;&#x4F59;&#x5F26;&#xFF08;hyperbolic cosine&#xFF09;</li>
<li>Math.expm1(x)    &#x8FD4;&#x56DE;e&#x2C6;x - 1</li>
<li>Math.fround(x) &#x8FD4;&#x56DE;x&#x7684;&#x5355;&#x7CBE;&#x5EA6;&#x6D6E;&#x70B9;&#x6570;&#x5F62;&#x5F0F;</li>
<li>Math.hypot(...values)    &#x8FD4;&#x56DE;&#x6240;&#x6709;&#x53C2;&#x6570;&#x7684;&#x5E73;&#x65B9;&#x548C;&#x7684;&#x5E73;&#x65B9;&#x6839;</li>
<li>Math.imul(x, y) &#x8FD4;&#x56DE;&#x4E24;&#x4E2A;&#x53C2;&#x6570;&#x4EE5;32&#x4F4D;&#x6574;&#x6570;&#x5F62;&#x5F0F;&#x76F8;&#x4E58;&#x7684;&#x7ED3;&#x679C;</li>
<li>Math.log1p(x)    &#x8FD4;&#x56DE;1 + x&#x7684;&#x81EA;&#x7136;&#x5BF9;&#x6570;</li>
<li>Math.log10(x) &#x8FD4;&#x56DE;&#x4EE5;10&#x4E3A;&#x5E95;&#x7684;x&#x7684;&#x5BF9;&#x6570;</li>
<li>Math.log2(x) &#x8FD4;&#x56DE;&#x4EE5;2&#x4E3A;&#x5E95;&#x7684;x&#x7684;&#x5BF9;&#x6570;</li>
<li>Math.sign(x) &#x5982;&#x679C;x&#x4E3A;&#x8D1F;&#x8FD4;&#x56DE;-1&#xFF0C;x&#x4E3A;0&#x8FD4;&#x56DE;0&#xFF0C;x&#x4E3A;&#x6B63;&#x8FD4;&#x56DE;1</li>
<li>Math.tanh(x)    &#x8FD4;&#x56DE;x&#x7684;&#x53CC;&#x66F2;&#x6B63;&#x5207;&#xFF08;hyperbolic tangent&#xFF09;</li>
</ul>

                    
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